20 may 1968 & seller of mlk items

#OTD-ish 20 May 1968 Washingtonians would have been familiar with this seller of Rev. Dr. Martin Luther King, Jr items. According to the Evening Star newspaper, he was "ever present." This photo was taken during the Mother's Day rally.  

The potential buyer is contemplating purchasing buttons with King's images on them and photographs of King. There are at least three different button sizes and at least four different photos of King. 

The seller has a portable set-up for ease of movement. The board with the buttons seems to be resting on an easel and the photos can be carried away in the box. 

Your comments are welcome below. Did you, a family member or neighbor purchase an MLK item from this seller? Do you remember this seller? Do you recognize the person contemplating a purchase? Do you recognize the other person in the photo? I just noticed the label on the box. I'm going to return to the original photo and see if I can decipher it with a magnifying glass. You may comment privately here.

Photo source: Courtesy of DC Public Library Special Collections. Poor People's Campaign Collection. 12 May 1968. Owen Duvall, photographer.